Virtual reality (VR) systems allow a user to become immersed in a virtual environment by displaying the virtual environment, sensing the position and movement of the user, and responding to the position and movement of the user. VR games often rely on wearable devices or other devices that sense natural movements of the user. For example, rather than operating a joystick to throw punches in a boxing game, the boxing game may receive input regarding the actual positions and movements of a user's hands, so that the user is able play the game by actually punching with their arms and hands. Similarly, a virtual reality system may allow a user to move through a displayed virtual environment by taking physical steps, to grasp objects, to press virtual buttons, and so forth.
In some systems, a user may wear or hold what are referred to as VR controllers. A VR controller is a device that provides output such as audio and video to a user. For example, a user may wear a VR headset that displays the virtual environment to the user. A VR controller may also accept or detect user input, allowing the user to interact with or move relative to elements of the virtual environment. Specifically, some VR controllers detect user positions and movements.
The position and movement of a user may be detected in various ways. In some systems, optical techniques are used to detect user movement. In particular, some systems may use light sensors, positioned on wearable or handheld devices such as VR headsets or VR hand controllers, to detect optical signals that convey position information.
A VR controller typically operates wirelessly, using rechargeable batteries for power. The useable time of the VR controller is therefore limited by the available battery capacity. Accordingly, it is important to minimize or limit the power consumption of VR controllers.